FIELD OF THE INVENTION
The present invention relates to wash systems for milking parlors, and more particularly to a system, apparatus and method for a back flush wash system for a carousel or rotary type milking parlor.
The carousel type milking parlor has been in use for a number of years, and it comprises a rotary platform with stalls (milking stations) positioned circumferentially around the rotary platform. There is an entry and exit location where the cows to be milked are individually led into the stalls. At that time the "claws" of the milking machine are attached to their udders, and the milking process begins, with the machine extracting milk from the cows and delivering the milk to a collecting location.
The milking operation continues as each individual cow is carried in a circular path, and the rate of rotation of the platform is gauged so that the milking of each cow is completed before the cow reaches the exit station at the inlet/outlet area. Prior to the time that each cow arrives at the exit station, the milking operation for that cow has been completed, so that an appropriate sensor in the milking apparatus shuts off the suction to the milking apparatus attached to that particular cow. This causes the "claw" to automatically become disengaged from the cow. When that cow reaches the exit area, she is moved off the platform.
For sanitary reasons (i.e. reducing the possibility of a disease being transmitted from one cow to the other), it is not uncommon for milking parlors to be provided with a back flush washing system for the individual milking machines. In a rotary (carousel-type) milking parlor, this is commonly accomplished by installing a wash liquid supply line around the circumference of the rotating platform, and there are individual conduits from this wash liquid supply line leading to a valve positioned in the transfer line at each milking station. Each such valve has a first position where the milk from the cow is directed from the individual milk machine through a milk carrying conduit to a collecting location. When the back flush operation is to take place (after the milking process for that individual cow has been completed and the claw has dropped off from the udder of the cow), the valve switches over to its back flush position where it makes a connection to the wash liquid line to direct the wash liquid through the valve and in a reverse direction through the portion of the transfer line that leads to the claw. The wash liquid can simply be warm water, and in some instances a disinfectant is also directed through the line and through the milk machine, followed by a water rinse.
At the completion of the washing for that individual milk machine, the transfer line and the machine are cleared of the wash liquid, either by blowing air through the wash liquid tube and the related portion of the transfer line, or a suction is applied to draw the remaining wash water back to its source.
In the prior art back flush systems, at every stall, there is provided a back flush valve which in turn is connected to its own timing mechanism, which will cause the control valve to move from its milking position to the back flush position and then back to the milking position at certain times in this cycle. Each milk station is provided with its own valve, and also its own line connected to the main source of wash liquid.
In 1979, U.S. Pat. No. 4,145,992 (Rafaely) issued, this being entitled, "System For Washing Milking Cups In A Rotary Milking Machine". This patent discloses a washing system for a rotary milking parlor where the platform is provided with a plurality of wash liquid inlet devices 22, one for each of the milking stations, with each of these devices connected by a conduit 24 through a control valve 18 which in turn connects to its related milking unit 12.
All of the fluid inlets in the devices are carried by (and rotate with) the platform 2 and are positioned to be engaged by a single nozzle 26 at the entry and exit location. This nozzle 26 is carried by a piston 30 which is movable within a cylinder 32 that is pivotally mounted to a base 33 which is at a fixed location. This nozzle 26 is connected to a conduit 34 which is selectively supplied with water from a central water source, compressed air from a compressed air source, and a sterilizing agent from a sterilizing agent source.
When each of the fluid inlet devices 22 reaches a particular location near the wash liquid discharge nozzle 26, a control mechanism causes the piston 30 in the cylinder 32 to extend outwardly so that the nozzle 26 comes into engagement with the fluid inlet device 22. Then a control mechanism causes the back flush washing cycle to take place.
A typical cycle can be where the wash water is discharged for two seconds, this being followed by an application of compressed air and a sterilizing agent. There is a "dwell" to permit the sterilizing agent to act (for example) for four seconds, after which more wash water is applied, and then compressed air to remove the water from the line. While this is happening, the cylinder and piston assembly 30/32 is moving in an arcuate path about its fixed base 33. When the piston assembly 30-32 reaches a certain location in its arcuate path of travel, it triggers a control member which causes the piston 32 to retract, thus disengaging the nozzle 26 from the fluid inlet device 22. A tension spring 88 attached to the cylinder 32 then pulls the piston/cylinder assembly 30/32 back to its original position as shown in the drawing of U.S. Pat. No. 4,145,992.
The control mechanism for this system comprises a plurality of control members 66 fixedly mounted at regularly spaced intervals to the rotary platform at a pre-determined distance from its related fluid inlet device 22. The control elements 66 sequentially engage a fixedly mounted control member 68 which moves a valve element in the control member 68 to cause a valve element (piston 94) in a fluid control device 72 to move from the position shown in the Figure of this patent to the right. This causes fluid to flow through the line 74 (which is mistakenly identified as 44 in the drawing) to cause the piston 30 to extend to cause the engagement of the nozzle 26 with the fluid inlet device 22 with which it is aligned. Then when the piston/cylinder 30/32 reaches its end limit of angular travel, it engages a further control member 78 which directs fluid to the control valve 72 to cause a valve element 94 to move back to its original position, so that the piston 30 is caused to retract.
The wash cycle is controlled by a timer 48 (not shown in the drawing, but presumably being the rectangle in which the knobs 56, 58 and 60 are located). The timer is triggered by a pressure switch 64 within the chamber 72 of the cylinder 32, this switch 64 sensing when the piston 30 has completed its movement to its projected position, this being sensed by the sudden rise of pressure in the chamber 76, at which time the switch 64 transmit an electrical signal, via the line 62, to the timer 48.
To the best knowledge of the applicant herein, the washing system disclosed in U.S. Pat. No. 4,145,992 has either not been commercially implemented in the dairy industry, or at least has not been widely commercialized in the dairy industry.
U.S. Pat. No. 3,999,517 (Anderson) shows a rotary milking parlor having a plurality of milking units 9, each of which discharges its milk into a related receiving vessel 6. Each of the receiving vessels 6 has a coupling means 10 which comes into engagement with a matching member 3 which is moved by a pneumatic cylinder 4 into and out of engagement with the member 10. This member 3 is in turn mounted to an arm 1 which in turn is pivotally connected to a swing arm 1 mounted at a fixed location.
As the receiving vessel 6 moves along its arcuate path when its coupling member 10 is exactly above the coupling member 3 the coupling member 3 is raised by the pneumatic cylinder 4 to engage a coupling means 10. As the receiving vessel 6 moves further along the arms 1 and 2 move along with it, during which time, the milk is being discharged into the tube 5 and into the container 8.